An aircraft was unveiled Friday in Switzerland that aims to take off with one pilot aboard and fly day and night propelled only by solar energy, flying around the world without expending any fuel or expelling any pollution. The team led by Bertrand Piccard and Andre Borschberg believes the goal is unachievable "without pushing back the current technological limits in all fields." The craft measures 61 meters in span and will carry aloft about 3300 pounds of aircraft and 12,000 photovoltaic cells. There are more efficient options, but the 130-micron monocrystalline silicon solar cells were chosen for their combination of light weight and efficiency. The cells are dispersed over 200 square meters of surface area as part of a 12 percent efficient propulsion chain designed to deliver about eight horsepower from four motors. The motors are housed in under wing pods with lithium polymer batteries that are insulated to conserve the radiated heat that will allow them to function at the -40 degrees Centigrade at 27,000 feet the aircraft may experience. Power collected from the solar cells and stored in the batteries will be used to drive 3.5-meter propellers through a gear reduction that will swing them at 200-400 revolutions per minute -- lifting the giant craft off the ground at about 19 knots and flying it at about 60. And then there's what's on the inside.

Aside from a pilot, the aircraft will also be carrying an on-board computer to analyze and manage hundreds of parameters that it will transfer to a ground team and simplify the task for the pilot. The system is designed to manage optimal power for the motors in every possible flight configuration and battery charge or discharge condition. If it works as intended it will allow the plane to "self-correct and minimize its energy consumption." What its designers hope is the beginning of the ultimate alternative fuel vehicle is here. Let the testing begin.

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Picture of the Week

As aviation photos go, this was the best this week but there are some great beauty shots when you click through. In the meantime, congratulations to Daniel Gillette for this very nice photo he calls Sunset Pitch-Out. The photo is copyrighted by Gillette.